


Saber and The Black Knight

by Pokibal2001



Category: Fate/Prototype: Fragments of Sky Silver, Fate/stay night & Related Fandoms, Sonic the Hedgehog (Video Games)
Genre: Adventure & Romance, Angst and Hurt/Comfort, Canon-Typical Violence, Crossover, Crossovers & Fandom Fusions, F/M, Friendship, Gen, Grief/Mourning, Implied/Referenced Character Death, Self-Indulgent
Language: English
Status: In-Progress
Published: 2021-01-31
Updated: 2021-02-14
Packaged: 2021-03-18 03:22:17
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,913
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29111499
Author URL: https://archiveofourown.org/users/Pokibal2001/pseuds/Pokibal2001
Summary: It wasn't supposed to go like this. The mistake should have never happened. A blooming flower destined to wither persists regardless of its destiny, and Camelot shall suffer for denying its fate.Saber has been summoned to a seemingly nostalgic yet vastly different timeline where Camelot has yet to fall, ruled by an black-tainted immortal that oppresses Albion with tyranny and fell creatures with his only guide being an enigmatic Wizard that claims to be the successor of the Flower Magus, Merlin.Will Saber figure out the truth in this alternate reality of his past, or will he submit to the eternity of denial that lurks in the shadows beneath?
Relationships: Merlin (Fate/Prototype)/Arthur Pendragon | Saber
Comments: 3
Kudos: 14





	1. Once and Future Summoning

**Author's Note:**

> Also, it's important to note that apart from Merlina, no other Sonic characters will be appearing in this game as the Arthurian characters will be represented by their Fate counterparts instead since the Fate aspect of the crossover is the far more domninat one. This crossover is not so much of Sonic x Fate fanfic, but more of a Fate x Black Knight fanfic, so any chances of seeing Sonic or any other related character is nil.

Winds bellow under the overcast sky, the dreary clouds looming over the wild plains of a once prosperous kingdom.

A raven scavenging for the barebones meat of a cow’s corpse squawked in sheer terror and flew away as a hooded mage ran in panicky fervour on the dirt path that trailed across the hills.

Behind the mage came an impossible cacophony of a horse’s clopping above her, as though it was galloping through the air itself.

The faerie horse has never once neighed nor does its armour rustled with metallic chicks, dashing towards the sky with not an ounce of sound save for the impossibly loud steps of its hooves. On its back was the rider, a knight clad in jet black armour lined with crimson patterns.

Beneath his helmet, he narrowed his slitted gold eyes at his target.

With a swinging slash of his sword shrouded in shadow, a wave of destructive darkness spreads out and hit the ground right in front of the hooded mage. The resulting impact led a crater that nearly levelled the hillside and sent the mage flying backwards with her hood forced open. 

The mage quickly rose from the ground and glanced forlornly at the ruined path that laid beyond her, blocking her way. Trapped between a rock and a hard place as she could hear the Black Knight drawing closer, she hardened her resolve.

Staring back defiantly at the approaching knight, she gripped her staff harshly as she remembered her one last trump card.

Slamming the bottom point of her staff onto the floor, ritualistic circles of magical light formed on the ground as she quickly chanted the appropriate verses for her spell.

A summoning circle, to be precise.

The Black Knight, realizing the true intent of the mage’s spell, quickly proceeded to jump off his faerie horse’s back and dashed towards her with his blackened sword at hand.

“O brave knight, swift as the wind! Heed my call!”

As if answering her prayers, a pillar of light made manifest from the summoning circle, one that shines a silvery blue laced with golden hues. As it rises into the overcast sky, the sheer intensity of the magical pressure exerted by the summoning forces the Black Knight to retreat with a frustrated hiss.

Amidst the sea of grey clouds, there was a hole where the light pillar pierced through. A waterfall of moonlight came trickling down from the starry heavens, a small portal swirling in the middle of said hole.

From that portal dropped a knight of sky silver.

Gasping in realization that he was falling on his back, the hooded knight swiftly reacted by performing a plunging action with his holy sword towards the ground.

Clouds of dust gathered around the knight as he made impact, his own hood flew back open.

As the dusty clouds settled, the mage let out a gasp upon seeing her summoned saviour whose face was no longer concealed by his hood. Ruffled hair of sunshine gold and a stern emerald gaze, the knight clad in burnished silver armour stood up as he pulled Excalibur out of the ground.

The mage intended to introduce herself but could not withhold her awed expression, “You are…!”

The silver knight turned to glance at the mage in acknowledgement, a stern frown on his normally affable face, “Are you the magus who summoned me?”

Before the mage could properly reply, there was a furious roar and the clashing of steel that came after. The mage watched in shock as the silver knight reflexively parried the black knight’s assault, the holy sword inlaid with blue and gold designs colliding against the blackened blade lined with crimson patterns.

The silver knight’s green eyes widened in disbelieving shock as he stared at the other knight’s helmet, “That’s…!”

With a burst of effort, the silver knight successfully knocked back the black knight and jumped backwards to create space between them as to maintain his bearings. The black knight, however, remained relentless as he quickly pounced on the other knight with powerful swings of his blackened blade.

The mage continued to watch the fight from a safe distance in utmost awe as the battle between both knights has nearly levelled the hills around them, her summoned saviour parrying the ruthless assaults of the black knight into a stalemate.

With gritted teeth, the black knight had his patience tested to his limits and jumped back, the misty darkness that swirled agitatedly around his blackened blade was suddenly accompanied by a crackle of crimson and magenta lightning.

Tainted sword held high in both hands; the black knight spoke in a gravelled tone that echoes beneath his helmet.

**_“Iron Hammer of the Hollow King.”_ **

The silver knight stilled, green eyes flashing in horrified recognition as his grip on the pommel tightened.

“What have you done?” He whispered, watching despairingly as the once holy sword held in the black knight’s hand no longer gleams in the light of victory but instead, howls in a promised storm of bloodlust and shadows.

**“Reverse the Rising Sun.”**

With not a moment to lose, the silver knight quickly reacted by bringing his own holy sword up as he prepared to release the seals engraved onto the glowing blade.

**“Seal 13, Decision Start!”**

Pillars of light erupted from the ground behind the silver knight as glowing gold motes gathered around the holy sword held in his hand.

However, before the silver knight could even begin undoing the seals, there was a gasp of horror and a sudden tug that was strong enough to pull away his arm, interrupting his Noble Phantasm as the golden spectacle that gathered around them dissipated into nothing.

The silver knight turned his head to the mage, slightly aggravated and panicking, “What are you-?!”

The mage shook her head as she exclaimed, “We must leave now!”

**“Swallow the Light!”**

With an urgent flourish of her staff and a determined gleam in her unusually bright blue eyes, the mages chanted her spell.

**_“EXCALIBUR!”_ **

Wind swirled around them into a stormy vortex that spirited them away into a temporary safe haven from afar, just a few seconds shy before the torrent of darkness came razing the hillside plains where they once stood, till naught but ashes and shadows remained.

The black knight, slightly winded from expanding so much hateful miasma into his fallen blade, narrowed his eyes upon sensing minute traces of magic that was not his own in the air. The realization that a teleportation spell took place and the sheer audacity of such an infuriating act led the black knight to the boiling point.

Forcefully ripping the entire helmet from his head, the black knight’s golden eyes were slitted in pure rage as he raised his head up high and unleashed a bone-chilling roar far too inhuman to be natural.

From a far-off distance, a lone white lily flower growing on the cliff immediately withered.

On said cliff, trio of knights stood as unflinching witnesses. Despite their stern countenance befitting of their position, the devastating sight of that miasmic tower erupting from the ground unleashed by none other than their King trickled fear into their mind.

Subtly letting out an exhausted sigh, Sir Galahad briefly glances at his fellow knights.

Sir Gawain remained stalwart in his posture, but there was no doubt a hint of despair that overshadowed his stoic expression. Sir Lancelot simply looked troubled and despite Galahad’s own reservations about him, the naked sorrow on Lancelot’s face brought him no comfort.

Galahad then turned his gaze towards the wilted white lily flower, a dark omen of what was to come.

“The King has changed,” Galahad muttered softly to himself, his disheartened amber eyes closing, “And so has this Kingdom.”

\--

_“Merlin?”_

_A weary and battle-worn voice called out, and a certain Flower Magus flickered by his side._

_“What is wrong, my King?” The white-hooded wizard never failed to answer, her voice riddled with her usual playfulness, “Do you need anything?”_

_The deceptively youthful King stares at her in serious contemplation, “By any chance my death comes unexpected, can I trust you to find a successor and keep Camelot going?”_

_There was an initial silence, tense and forlorn, as it stretches on uncomfortably until Merlin finally replied in an atypically solemn tone, “…No, it will not come to that. I will not let your death happen.”_

_The King let out an exasperated sigh, “I figured.”_

\--

“Why did you stop me?” The silver knight questioned the mage harshly as they arrived on the glade, his green eyes narrowed, “I was about to counter the wanton destruction that black knight was committing.”

The mage shook her head, looking apprehensive as she cast her gaze down, “Even on the off chance that you do succeed in the clash of holy and fell energies between your swords, you would still not be able to wound him.”

“And why is that?” The silver knight raised his eyebrows, though the niggling suspicion in the back of his mind knew the answer.

The mage looked up to the silver knight with a grim expression, “Immortality. He bears the once holy scabbard of Excalibur, Avalon.”

The silver knight stiffened, his face paling at the implications of what the mage had said.

“Then that helmet, the sword he wielded…” the silver knight murmured in horror, a faraway look in his distracted green eyes, “It can’t be.”

“It is as you suspected, sir knight,” the mage nodded her head, “He is King Arthur, the Dark-Tainted Tyrant of Camelot.”

The silver knight let out a tired sigh, looking almost mournful as he closed his eyes and shook his head.

“…Is that why you summoned me?” His green eyes open, and the mage found herself shivering slightly underneath his familiar gaze of ironclad steel, “Here, in this twisted Camelot?”

“Yes,” The mage replied with a nod, relief clear in her voice, “I am truly glad to see you here, King Arthur of another World.”

Arthur Pendragon narrowed his eyes, “That I am. And who might you be?”

“Let me introduce myself properly,” Putting on her hood, the mage bowed slightly before smiling at him, “I am Merlina the Wizard, former Royal Court Mage of Camelot.”


	2. Concealing Pride

**Summary for the Chapter:**

> Arthur attempts to learn more about this alternate timeline of the Camelot he once cherished but he soon learns that being a natural magnet for trouble tends to get in the way of information a lot, frustratingly enough. Merlina, on the other hand, finds herself far too satisfied with the results of her summoning spell.

**Notes for the Chapter:**

> And here's chapter 2 at last! Certain dialouges are borrowed from the game, with some lines being slightly altered to fit with the context of the story.

Arthur dutifully followed the enigmatic Wizard from behind, his green gaze beholding a sceptical glint.

It cannot be a coincidence that Merlina just happens to be close dead-ringer to a certain Flower Magus he knows all too well. The elfish ears, druidic staff, sage-like garments and even the name… If it were not for the fact that Merlina’s magic felt distinctly different to his honed senses, he would have assumed that she was Merlin herself in a convincingly humble disguise that hid her signature colours.

As it stands, Merlina was obviously not his dear friend, but she was someone that must be related to her. Though Merlin does not talk about her family very much, if not at all, he would not be surprised if they do exist. So, the very possibility that she might have a long-lost relative, however slim it may be, was very likely.

But if that was the case, why was Merlina the successor of the previous Wizard in this alternate Camelot? What happened to the original Merlin of this twisted world?

As they traversed alongside a calm river that leads up to a lake in the middle of a misty forest, he attentively listened to the Wizard’s explanation of what has gone exactly wrong in this alternate version of a Camelot that he had never thought to see again.

“Just as the legends say, the Dark-Tainted Tyrant was once a wise and just ruler,” Merlina started, looking up into the overcast sky, “Blessed with noble knights and praised by all.”

Arthur thought of his own Knights. Gawain, Galahad, Tristan, Bedivere, Gareth, Percival and many of the others in the Round Table. Even Lancelot and Mordred. He remembered fondly of the times they shared together, of their daily misadventures, honorary duels and heartening meals alike. Despite how increasingly sparse those precious moments became the further his own reign as King continued, he would always cherish those that stood by side.

Feeling that familiar ache of longing and nostalgia in his chest, Arthur inhaled deeply to distract himself before asking the obvious question.

“Then what went wrong? How did he become the Tyrant?”

Merlina turned to look at him, her eyes cloudy with anticipation, “I believe the Lady of the Lake, Viviane might be at fault here.”

There was a sudden ripple in the once calm waters of the river, the mist that surrounds them grew cold and heavy in its pressure. The two of them stopped in their tracks, warily watching their surroundings.

“… I hope you thread carefully with your words, Merlina,” Arthur cautioned her, his hand readily gripping the hilt of his sword as his focused gaze searched for any sign of danger, “The Fair Folk don’t take kindly to accusations like that, and Lady Viviane is no exception.”

“I know,” Merlina sighed, hugging her staff closer, “Which is precisely why I must tell you how it happened.”

Arthur nodded, not once faltering his guard as he side-eyed the thickening mist, “By all means, continue.”

Merlina took in a deep breath, “The Lady of the Lake gifted the King with the holy scabbard, Avalon. However, she told him that to permanently own such a powerful artifact, he must venture forth on a quest into the heart of the Underworld.”

That was odd. He remembered Avalon being gifted to him as it was. Perhaps, again, that must have been one of the key differences between events of his time and this alternate reality. 

Apart from that...

“Underworld?” Arthur glanced at her quizzically, not familiar with the term.

“Yes, the Underworld,” There is a certain furor in Merlina’s sparkling blue eyes, almost as if they were enchanted, “A malignant realm of shadows, where it’s fell influence terrorises the locals at night. It is the source of the Tyrant’s dark powers.”

Arthur rubbed his chin in contemplation, realizing from the description of the Underworld that it was exactly the same realm as the Otherworld that he and Gwynn had once traversed back then. Only, it came by an obviously different name and lacks the same association it has with the dead.

“What happened exactly during his quest?” The silver knight asked with his brows furrowed, a quiet dread seeping into his exposed skin. 

“Despite the blessing that the Lady provided him as protection against its influence, a fragment of the Underworld latches onto Avalon and corrupted it,” Merlina looked a little stricken and even a tad bewildered upon explaining this, and the humidity in the air thickens even more, “A curse so subtle not even the Lady could sense it.”

The first drops of rainfall splattered on Arthur’s nose, causing it to wrinkle as he looked up to the overcast sky. Flashes of lightning loomed in the dark, grey clouds as the wind current grew violent.

Suddenly, he felt Merlina grab for his hand and dragging him along on the path into a half-run.

“We must move with haste,” the Wizard says as she warily eyes the rippling waters of the river, churning into waves of fury that threatens to splash at their feet and drag them into the depths, “If we can reach the lake in time, we can cross the moat and take shelter in the ruins there.”

Arthur’s mouth thinned, as he followed her stride, “Lady Viviane isn’t happy with you.”

Merlina shook her head, “Indeed she is not. She does not like people knowing the truth.”

Another howl of the wind, and Arthur hurriedly asked her, “Is there more to this story?”

“Yes. The corrupted scabbard wasted away at the King’s mind until he becomes the Dark-Tainted Tyrant of Camelot, plunging the Kingdom into a world of horror and chaos as he goes!”

There was a draconic roar, one so ear-splitting that Arthur groaned as he brought one hand to his battered ears. As soon as he regained his bearings, a certain sharpness filled the air, and he suddenly heard the sudden rapids of stormy waters surging through-

Arthur tightly gripped Merlina’s hand and jumped into a nearby bush, narrowly avoiding a splash of steaming hot water that exploded upon impact with the ground that they were standing previously on.

“The Ruler of Misty Lake!” Merlina gasped, her grip on her staff tightening as she looked up in horror.

Arthur followed her horrified gaze and his own green eyes widened slightly to see a Dragon the size of Camelot’s castle walls, the gargantuan Phantasmal flapping its wings with the sheer force of a brewing storm as it flew over the canopy of the misty forest in search of its prey.

“The ruler?” Arthur asked, brandishing his holy sword.

“Yes, Misty Lake is marked by that Dragon as its territory,” Merlina explained once more, warily staring at the sky as she huddled closer to the silver knight beside her, “Normally, its docile for as long as you do not defile its domain, but it seems to become the Lady’s attack dog for this occasion.

“I see…” Arthur quirked his eyebrow a little at how close the mage was but dismissed the unusual thought as he focused on other more important priorities, “I know what I have to do.”

Merlina turned to look at him in surprise, “Sir Arthur, what are you-?”

“Merlina, take shelter in the ruins. I’ll distract the dragon and lure it towards the other side of the lake,” The blond man looking almost ready to run, “That way I have more space to battle it.”

Merlina stared at him in awe and admiration, before taking in a deep breath and nodded, “Alright, I have faith in your abilities to best that Dragon.”

The mage immediately muttered a spell under her breath, and teleported towards whatever ruins Arthur hopes she takes shelter in.

Another ear-piercing roar and Arthur narrowed his eyes at the dragon, steadied his sword hand and sprinted towards the open.

\--

_“Want to know an interesting fact about dragons, My King?” Merlin winked with a glint of mischief at the bemused Arthur._

_“We both know you can just call me by my name, right?” Arthur shook his exasperatedly, smiling as he gathered the manuscripts on his working desk, “But sure, go ahead.”_

_Merlin grinned as she floated herself up, only to settle down by sitting on the edge of his desk, “So did you know? The sentimental vanity of a dragon’s horn is equal to a human’s hair on their head?”_

_“Is that so?” Arthur humoured her factual statements with an inquisitive smile, “So the bigger the horn, the better-looking it is?”_

_“Pretty close. It’s both size and beauty that determines the pride of having a great dragon’s horn,” Merlin pointing her finger up as though she was in a middle of a lecture, before covering her mouth as she giggles, “Dragons, they do love to show off, do they?”_

_“Kind of a like humans, actually,” Arthur snorted, thinking back towards the recent duels between his knights, “I guess no matter the species, there’s always the matter of pride.”_

_“Indeed,” Merlin nodded in agreement. Then, her lips quirked up even more into a mischievous grin, “I wonder what happens if a dragon’s horn gets cut off? Would the humiliation be the same as forcefully shaving off all the hair on a human until they’re completely bald?”_

_Arthur winced at the image, understanding the comparison, “That would be very unpleasant. I wouldn’t dare think how I react if that happened to-” Realization struck as suspicion glinted in his green eyes, “Merlin, what did you do?”_

_“Whatever do you mean?” Merlin smiled shamelessly, feigning total ignorance._

_“KING ARTHUR, CONTROL YOUR WIZARD THIS INSTANT!”_

_Arthur and Merlin turned to the muffled shrieks of an incredibly insulted visiting nobleman behind the door, no doubt running about in the castle’s corridors with the lack of dignity and hair._

_“… It’ll grow back in a day, I’m sure it will.”_

_“Merlin…” Arthur pinched the top of his nose, resisting the urge to curve his lips up into a shameless grin, “I’m no fonder of Marquees Drake than you do, but Kay is not going to be happy about this.”_

_“Okay, okay, I’ll help sort out this mess!” Merlin burst out a laugh, gliding towards the door with a skip in her airy steps. She turned back to Arthur with a bright smile, riddled not with the usual zest of mischief, but with a tender fondness that always leaves him breathless, “But I wonder, if you were a dragon, I would say your horn would be the most magnificent indeed.”_

\--

Merlina, having quickly casted a small-scale warding spell upon the ruins that she took shelter in so as to prevent anymore unwanted incidents from a certain Lady, watches through the open window with naked awe on her face. From an outsider’s perspective, it was a surreal battle that bordered almost like a scene out of a fairy tale.

A strong and handsome knight battling a ferocious dragon to protect the damsel in distress.

Letting out a relieved sigh, Merlina closed her eyes in content, relishing in the pained roars of the attack dog set upon her party by that infuriating Lady as she reflects on the past hectic hour.

The spell that she used to summon the silver knight earlier was meant to call for a random hero with a compability most suited to her needs had it been casted properly. Unfortunately, the Dark Illusion forced her hand too early with a premature summoning that she was so afraid that the ritual would fail just as it starts.

And yet... Never had she thought her summoning spell would end up bringing a parallel version of King Arthur himself into her World.

A King Arthur immortalised in his prime, one that was not corrupted by the grief and tragedy that taints this aging farce of a kingdom.

Merlina opens her eyes and her lips curved up in glee as she eagerly watches the beautiful sight that laid before her. King Arthur pragmatically hacked away at the horn that adorned the forehead of the Mist Dragon in the right window of time until the horn’s eventual demise, causing the whimpering beast to flee in its humiliation.

Leave it to King Arthur to recognise a Dragon’s personal pride and ruthlessly crush it till naught but dust left in its wake.

It was a bit of a pity that he did not slay it, they could easily deprive that wretched Lady what few of her precious allies that acts as threat to the ideal Camelot that she envisioned. Nevertheless, King Arthur still managed to surpass many of her expectations with flying colours.

After all, how wondrous it would be to have a King Arthur that recognises mercy as a boon and could still twist it into a weapon that strikes at one’s pride?

Seeing King Arthur walking back with his head held high, Merlina schooled her excited countenance into that of reserved satisfation as she left the ruins to greet him with a spring in her steps.

She has finally found a pure and righteous King Arthur, one as worthy as the legends say.

And no one, not the Tyrant, not the Lady nor even the _Merlin_ of the outside, shall stop her from granting Camelot and their King the merciful eternity that they _deserve._

**Notes for the Chapter:**

> And here's the end of chap 2! Sorry for the long wait, I'm not exactly sure when the next posting will be but I'll assure, I will get them out soon enough. Stay tune for the next chap!

**Author's Note:**

> And so begins the epic story of the Fate/Prototype x Sonic and the Black Knight crossover! I have this plot bunny jumping around for a while now, so I'm glad that I got to flesh this out while I could. I always wanted to see how Saber, more specifically the Prototype Saber of the Nasuverse, would react to such a situation where he would face himself as a tyrant (read: Alter). Take your time to read and I hope you'll enjoy the fanfic along the way.


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